The 'at' sign (@) means "execute" in RDO, just as in DCL. When
    you type @ and the name of an indirect command file, RDO executes
    the statements in the file as if you had typed them one at a time
    at the RDO prompt. The default file type for an indirect command
    file is RDO. You can use the SET VERIFY statement to have the
    commands in the file displayed on the screen as they execute.

    Example:

    $ TYPE ACCOUNTING.RDO
    INVOKE DATABASE FILENAME "DEPT3:ACCOUNTING"
    SHOW DATABASES
    $ RDO
    RDO> @ACCOUNTING
    Database with filename ACCOUNTING